Help: PSU damaged
Hello,
since several weeks, I had a MK3 and by an large I was really fine with it. Print quality is really good, no major software issues were causing problems.
Just the last 2 week, I struggled a lot with jam in the nozzle / unit with PLA.
Because the better is killing the good, I already decided to upgrade the MK3 with a Zaribo frame. Dismounting the ED3 so was the perfect timing for converting the MK3 into a Zaribo MK3.
Last night I finished the conversion. One part during that conversation was the exchange of the 24V cables and the power outage signal cable into longer ones. I did this very carefully, all the conncetors have been mounted very professional (with a professional tool) and the cables were mounted also with care and without tension.
While switching it on the first time, the GFCI (Ground Fault Circuit Interrupter) switched an power was off in the apartment. My impression in that millisecond was that the problem was in the unit of the power socket.
Next, was that I dismounted the PSU from the frame and opened it (removing the bottom) the see I anything visible occurs. I still left all the cables connected to PSU and the RAMBO Board.
Next I switched power on once again, which might not have been the best idea. This now caused to PSU to destroy itself, that mean you could see and hear the several parts on the PCB were killed.
Now I need some good advice and therefore I have questions:
1: Any idea what could have happened?
2: Is it possible, that the Rambo board also has been killed?
3: Because Prusa don't have the PSU in the shop, is there any other good replacement on the market (no cheap and insecure china products)
4: What happens if I don't use the power outage detector, that means I would not connect it to the rambo (because I don't know if this is damaged too and I really don't need it).
5: Are there any other things, which I should consider?
best regards and thank you for your support ...
Thomas
Re: Help: PSU damaged
So after a first check, with and old analog power supply (24V, 6A) the Rambo seems to be fine, It starts, fan starts, stepper motors (all axis) works. 🙂
That means Question 2 and 4 are answered ...
Thomas
Re: Help: PSU damaged
1. If the GFI fired it sounds like a short to ground. Barring a miswire, a stray wire strand might have touched the case or a ground plane on the PC board. If you didn't use connectors that is easy to do. If you did use connectors make sure every strand got into the barrel before crimping/soldering and insulate the connector barrel if it isn't already insulated.
3. There is a long thread on PSU failures and replacement.
It seems that Meanwell power supplies are popular and easily obtained on Amazon.
4. Next time double check for proper connections and no cross connection orto ground with a multimeter before powering on.
Re: Help: PSU damaged
I replaced mine with an LRS350-24. The fan in the LRS was too loud for me, so I changed it too. If you go with any power supply that you have to have custom mounts for, make sure the chassis of the printer is grounded to the earth ground on the power supply. I added a jumper to the frame on mine to do this as the adapter brackets isolated the chassis of the power supply from the chassis of the printer.
Re: Help: PSU damaged
I'm using now a VOLTCRAFT FSP 2410 , which is a power supply for Labs. It is almost perfect for the printer. May be I keep it an just put it under the desk (there are nicer boxes on the market). 😉
Thanks,
Thomas
Re: Help: PSU damaged
I'm surprised it didn't have a fuse or something. Maybe it would be a good idea to add one given the problem some people have had with shorts developing over time (repetitive wire rubbing or something like that)?
Re: Help: PSU damaged
there shouldn't be any cable movement between the PSU and the einsy.
after that there are already fuses in place
regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
Re: Help: PSU damaged
Just as a last short feedback. I'm now 21 hours after start of a 45 hours print. Everything is pretty fine again.
For the time being I'll stay with the Voltcraft supply even if I don't have that "power outage" functionality anymore.
After a thorough inspection, it is definitely clear, the the issues started inside the power-supply.
Thanks for the input,
Thomas
Re: Help: PSU damaged
If you haven't, you might add a post to the PSU failures thread. So far Prusa denies any problem, so more evidence may be useful in eventually getting this issue addressed.